POS1237 MICROVASCULAR DAMAGE IN AUTOIMMUNE CONNECTIVE TISSUE DISEASES: A CAPILLAROSCOPIC ANALYSIS FROM 20 YEARS OF EXPERIENCE IN A EULAR TRAINING AND RESEARCH REFERRAL CENTER FOR IMAGING
Authors: E. Hysa, S. Sammorì, C. Pizzorni, E. Gotelli, A. Cere, C. Schenone, G. Ferrari, R. Campitiello, V. Gerli, S. Paolino, A. Sulli, V. Smith, M. Cutolo
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Nailfold videocapillaroscopy (NVC) safely allows the detection of microvascular damage which can vary in terms of extent and severity (validated NVC patterns) in patients with Raynaud's phenomenon (RP) secondary to autoimmune connective tissue diseases (CTDs). <h3>Objectives</h3> The prevalence of the morphological capillary findings was retrospectively evaluated in a wide cohort of patients with RP secondary to a CTD at the time of the first single NVC analysis, independently from their current treatment, autoantibody profile and comorbidities. <h3>Methods</h3> One-thousand-one-hundred-eighty-one (1181) patients affected by CTDs (1065 females, mean age 54.1 ± 16.2, mean disease duration 4.5 years ± 3) were analysed from 2001 to 2021. The considered CTDs, diagnosed through the classification criteria available at the time of the enrollment, included: systemic sclerosis (SSc, 51%), undifferentiated connective tissue disease (UCTD, 26%), mixed connective tissue disease (MCTD, 6%), dermatomyositis (DM, 3%), systemic lupus erythematosus (SLE, 9 %), Sjögren's syndrome (SS, 3%) and primary anti-phospholipid syndrome (aPS, 2%). The capillaroscopic parameters were classified according to the CAP Fast Track Algorithm and distinguished between scleroderma-pattern (specific NVC alterations) and non-scleroderma patterns (non-specific NVC alterations) [1]. The presence of specific NVC findings detectable with a progressive microangiopathy in SSc patients ("early", "active", "late" patterns) have been searched also in other CTDs, beyond SSc. The "scleroderma-like pattern" was defined when a concomitant mix of the specific abnormalities of the SSc-patterns (namely: giant capillaries, loss of capillaries, capillary dilations, microhaemorrhages, abnormal shapes) was detected without fitting the single definition of "Early", "Active" or "Late" pattern [2]. <h3>Results</h3> Among CTDs, the mean capillary density (1 linear mm) was significantly lower in SSc, DM and MCTD (respectively, 7.04 ± 0.18 vs 6.5 ± 0.75 vs 7.7 ± 0.48) compared with other CTDs. "Early", "Active" and "Late" NVC scleroderma patterns were detected in 34%, 38% and 16% of SSc patients, whereas the scleroderma-like pattern was found significantly more frequent in DM (63 %) and MCTD (37%). Giant capillaries, capillary dilations and microhaemorrages were significantly more frequent in SSc and DM compared with other CTDs (respectively in 73%, 99% and 70% of SSc patients e in 73%, 96% e 70% of DM patients, Figure 1). The non-specific abnormalities of capillary morphology, such as the ramifications (abnormal shapes as expression of neoangiogenesis) were significantly more frequent in SSc, MCTD and APS among all the CTDs (respectively, in 48%, 41% and 36% of cases). Moreover, giant capillaries and abnormal shapes were detected in 61% and 41% of MCTD patients. In APS, the most significant prevalence of microhaemorrages (50%) was observed compared with other CTDs, to the exclusion of SSc and DM being detectable in 70% of cases. No significant damages were observed in SS and SLE patients (Figure 1). <h3>Conclusion</h3> This large sample size of CTDs patients, collected over 20 years of analysis, confirms the highest specificity and severity of the NVC microvascular damage respectively in SSc and DM patients, when compared to other CTDs. Those data will be used to implement easy algorithms to distinguish scleroderma patterns, from non-scleroderma and scleroderma-like patterns. <h3>Reference</h3> [1]Smith V et al. Autoimmun Rev 2019 [2] Cutolo M et al. Nature Rev Rheumatol 2021 <h3>Acknowledgements</h3> Elvis Hysa, Silvia Sammorì and Carmen Pizzorni equally contributed to this work. <h3>Disclosure of Interests</h3> None Declared.